程序没有错的，应该是包的问题，看看版本等  // Create a new Job
     Job job = Job.getInstance();
     job.setJarByClass(MyJob.class);

     // Specify various job-specific parameters     
     job.setJobName("myjob");

     job.setInputPath(new Path("in"));
     job.setOutputPath(new Path("out"));

     job.setMapperClass(MyJob.MyMapper.class);
     job.setReducerClass(MyJob.MyReducer.class);

     // Submit the job, then poll for progress until the job is complete
     job.waitForCompletion(true);

用FileInputFormat.addInputPath()也同样出错，不解啊